DE447864C - Method for determining wall thickness or changes in cross-section of pipes - Google Patents

Method for determining wall thickness or changes in cross-section of pipes

Info

Publication number
DE447864C
DE447864C DEV21117D DEV0021117D DE447864C DE 447864 C DE447864 C DE 447864C DE V21117 D DEV21117 D DE V21117D DE V0021117 D DEV0021117 D DE V0021117D DE 447864 C DE447864 C DE 447864C
Authority
DE
Germany
Prior art keywords
cross
section
pipes
changes
wall thickness
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
DEV21117D
Other languages
German (de)
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
HEINZ VOIGT DR ING
Original Assignee
HEINZ VOIGT DR ING
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by HEINZ VOIGT DR ING filed Critical HEINZ VOIGT DR ING
Priority to DEV21117D priority Critical patent/DE447864C/en
Application granted granted Critical
Publication of DE447864C publication Critical patent/DE447864C/en
Expired legal-status Critical Current

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Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01BMEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B7/00Measuring arrangements characterised by the use of electric or magnetic techniques
    • G01B7/02Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness
    • G01B7/06Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness for measuring thickness
    • G01B7/10Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness for measuring thickness using magnetic means, e.g. by measuring change of reluctance
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01BMEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B7/00Measuring arrangements characterised by the use of electric or magnetic techniques
    • G01B7/30Measuring arrangements characterised by the use of electric or magnetic techniques for measuring angles or tapers; for testing the alignment of axes
    • G01B7/31Measuring arrangements characterised by the use of electric or magnetic techniques for measuring angles or tapers; for testing the alignment of axes for testing the alignment of axes
    • G01B7/312Measuring arrangements characterised by the use of electric or magnetic techniques for measuring angles or tapers; for testing the alignment of axes for testing the alignment of axes for measuring eccentricity, i.e. lateral shift between two parallel axes

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)

Description

Verfahren zum Feststellen von Wandstärken oder Querschnittsänderungen von Rohren. Zur Vermeidung von Kesselschäden müssen die einzubauenden Rohre genau auf Wandstärkenabweichungen und Walzfehler (Schlackeneinschüsse, Walzschiefer u. dgl.) untersucht werden. Für Kesselrohre, deren Länge in modernen Steilrohrkesseln bis zu 6 m beträgt, kann zur Zeit nur der an beiden Rohrenden sichtbare Querschnitt geprüft werden. Ein Verfahren, um schnell und sicher sämtliche, einzubauenden Rohre in ihrer ganzen hänge auf Fehler zu untersuchen, ist noch nicht gefunden. Die einzige Möglichkeit, deren man sich in einzelnen Fällen bediente, ist das Röntgendurchleuchtungsverfah.-ren, das sich aber nur schwer und mit großen Kosten verwenden läßt.Method for determining wall thicknesses or changes in cross-section of pipes. To avoid boiler damage, the pipes to be installed must be precise for wall thickness deviations and rolling defects (slag inclusions, rolled slate, etc.) Like.) are examined. For boiler tubes whose length is in modern steep tube boilers up to 6 m, only the cross-section visible at both pipe ends can currently be used being checked. A method to quickly and safely all pipes to be installed To investigate errors in its entirety has not yet been found. The only The option that was used in individual cases is the fluoroscopic procedure, but it is difficult and expensive to use.

Nachstehend werden verschiedene Verfahren beschrieben, welche in kürzester Zeit und mit einfachsten Mitteln eine für die Praxis hinreichend genaue Prüfungsmethode angeben. Sie beruhen darin, daß sämtliche Rohrquerschnitte schrittweise einem magnetischen oder elektrischen Kraftlinienfeld ausgesetzt werden, dessen durch Querschnittsänderung bedingte Feldstärkenänderung in. bekannter Weise meßbar ist, wobei der zu messende Körper als Teil des magnetischen oder elektrischen Kraftflusses benutzt wird. In Abb. i sei a ein beliebiger Querschnitt des in eine Drehbank gespannten und sich drehenden Rohres; b sei ein permanenter Stahlmagnet, dessen Pole c und d durch geeignete Distanzvorrichtungen immer einen gleichen Abstand e von dem äußeren Rohrumfang haben; f sei, eine Drahtspule und g ein Anzeige- oder Meßgerä.t. Dreht sich das Rohr, so wird in g so lange keine Verjänderung zu beobachten sein, als der Querschnitt a auf dem ganzen Kreisumfang konstant ist. Sobald jedoch eine Querschnittsveränderung vorhanden ist, ändert sich der von den Polen c und d durch den Querschnitt a hindurchtretende magnetische Kraftfluß, der sofort in dem Meßgerät g Stromschwankungen hervorruft.Various procedures are described below which, in the shortest possible time and with the simplest of means, provide an examination method that is sufficiently precise for practical use. They are based on the fact that all pipe cross-sections are gradually exposed to a magnetic or electrical line of force field, the change in field strength caused by the change in cross-section being measurable in a known manner, the body to be measured being used as part of the magnetic or electrical force flow. In Fig. I, let a be any cross-section of the rotating pipe clamped in a lathe; Let b be a permanent steel magnet, the poles c and d of which are always at the same distance e from the outer circumference of the pipe by means of suitable spacing devices; f is a wire coil, and g is a display or Meßgerä.t. If the tube rotates, no change will be observed in g as long as the cross section a is constant over the entire circumference. As soon as there is a change in cross-section, however, the magnetic flux of force passing through the cross-section a from the poles c and d changes, which immediately causes current fluctuations in the measuring device g.

Eine andere Anordnung des Magneten b ist in Abb. a gegeben. Der Magnet wird in der Längsrichtung des Rohres a hin und her bewegt; die auf ihm befindliche Spule läßt im Meßgerät g die durch Querschnittsveränderungen hervorgerufenen, magnetischen Kraftlinienschwankungen als elektrische Schwankungen- erkennen. In beiden Fällen ist es auch möglich, die Intensität der Anzeige dadurch zu steigern, daß man den Magneten durch eine Hilfsstromquelle (Gleich- oder Wechselstrom) erregt, wobei unter Umständen auf einen Stahlmagneten oder Eisenkern verzichtet werden kann. Auch kann durch einen feststehenden oder beweglichen Magneten oder Spule oder Draht ein magnetisches oder elektrisches Feld erzeugt werden, welches durch das zu prüfende Werkstück meßbar b.eeinflußt wird.Another arrangement of the magnet b is given in Fig. A. The magnet is reciprocated in the longitudinal direction of the pipe a; the one on him The coil leaves the magnetic in the measuring device g caused by changes in cross-section Recognize force line fluctuations as electrical fluctuations. In both cases it is also possible to increase the intensity of the display by using the Magnets excited by an auxiliary power source (direct or alternating current), whereby under Circumstances a steel magnet or iron core can be dispensed with can. Also can by a fixed or movable magnet or coil or Wire, a magnetic or electric field can be generated, which is generated by the The workpiece to be tested can be measured if it is influenced.

Eine weitere Lösung ist in Abb. 3 schematisch dargestellt.Another solution is shown schematically in Fig. 3.

Das sich drehende Rohr a wird in den Stromkreis einer Gleich- oder Wechselstromquelle h derart leingefügt, daß an beiden Enden des Rohres Kontaktscheiben i angeordnet werden, gegen die Bürsten k schleifen. Das Meßgerät l spricht in diesem Falle auf Feldschwankungen an, die durch die ungleichmäßige Stromverteilung im sich drehenden Rohr bei veränderlichen Querschnitten hervorgerufen werden.The rotating tube a is in the circuit of a DC or AC power source h inserted in such a way that contact washers at both ends of the tube i arranged to grind against the brush k. The measuring device 1 speaks in this Fall on field fluctuations caused by the uneven current distribution in itself rotating pipe with variable cross-sections.

In samtlichen Fällen können statt der Magneten mit Spulen als Anzeigevorrichtung auch eine oder mehrere Blattfedern nach Art der bekannten Zungenfrequenzmesser gewählt werden. Auch kann bei der Prüfung das Rohr stillstehen und das Prüfgerät um dieses herumbewegt werden.In all cases, magnets can be used as a display device instead of magnets also selected one or more leaf springs in the manner of the known reed frequency meter will. The pipe can also stand still during the test and the test device around it be moved around.

Claims (2)

PATENTANSPRÜCHE: r. Verfahren zum Feststellen von Wandstärken oder Querschnittsänderungen von Rohren, dadurch gekennzeichnet, daß sämtliche Rohrguerschnitte schrittweise einem magnetischen oder elektrischen. Kraftlinienfeld ausgesetzt werden, dessen durch Querschnittsänderung bedingte Feldstärkenänderung in bekannter Weise meßbar ist, wobei der zu messende Körper als Teil des magnetischen oder elektrischen Kraftflusses benutzt wird. PATENT CLAIMS: r. Method for determining wall thicknesses or Changes in cross-section of pipes, characterized in that all pipe cross-sections gradually a magnetic or electric. Force line field are exposed, its change in the field strength caused by the change in cross section in a known manner is measurable, with the body to be measured as part of the magnetic or electrical Power flow is used. 2. Verfahren nach Anspruch r, dadurch gekennzeichnet, daß durch den zu messenden Körper ein elektrischer Strom gesandt wird, wobei die bei ungleichmäßiger Wandstärke eintretende Änderung der elektromagnetischen Verhältnisse durch Anzeige- oder ?bIeßgeräte nachweisbar ist. 2. The method according to claim r, characterized in that an electric current is sent through the body to be measured, the change in the electromagnetic conditions occurring with uneven wall thickness being detectable by display or measuring devices.
DEV21117D 1926-03-24 1926-03-24 Method for determining wall thickness or changes in cross-section of pipes Expired DE447864C (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DEV21117D DE447864C (en) 1926-03-24 1926-03-24 Method for determining wall thickness or changes in cross-section of pipes

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEV21117D DE447864C (en) 1926-03-24 1926-03-24 Method for determining wall thickness or changes in cross-section of pipes

Publications (1)

Publication Number Publication Date
DE447864C true DE447864C (en) 1927-07-28

Family

ID=7578958

Family Applications (1)

Application Number Title Priority Date Filing Date
DEV21117D Expired DE447864C (en) 1926-03-24 1926-03-24 Method for determining wall thickness or changes in cross-section of pipes

Country Status (1)

Country Link
DE (1) DE447864C (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2439184A (en) * 1943-01-23 1948-04-06 Nat Pneumatic Co Magnetic flaw detector
DE1239484B (en) * 1955-03-26 1967-04-27 Fischer & Co E Device for determining the position of a core of a body consisting of a core and a jacket

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2439184A (en) * 1943-01-23 1948-04-06 Nat Pneumatic Co Magnetic flaw detector
DE1239484B (en) * 1955-03-26 1967-04-27 Fischer & Co E Device for determining the position of a core of a body consisting of a core and a jacket
DE1239484C2 (en) * 1955-03-26 1973-07-05 Fischer & Co E Device for determining the position of a core of a body consisting of a core and a sheath

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